Thanks to Friday’s snowbound triumph in Denver, the must-win pressure has receded from the U.S. national team just in time for the most difficult game of the Hexagonal—Tuesday night’s matchup with Mexico at the Estadio Azteca (10:30 p.m. ET, ESPN).

It has become one of the top rivalries in international soccer over the past two decades, but when it comes to World Cup qualifying the CONCACAF Clasico often is more about the battle between half-brothers for regional bragging rights than it is about berth in the finals. Think of it as Duke-North Carolina basketball, only with more projectiles—they’re desperate to beat each other, but in the end there’s not a ton at stake. Both likely will be at the big dance.

The U.S. and Mexico have played a home-and-home series in each of the past four World Cup cycles, splitting each one. There were two ties back in 1997 and wins for the home team in each qualifier since. That trend puts the pressure squarely on El Tri on Friday. At 0-0-2 and having already dropped points at home in last month’s draw with Jamaica, Mexico will anxious for a result at the Azteca.

Now in second place in the six team final round at 1-1-0 following last week’s 1-0 win over Costa Rica, the U.S. has little to lose.

"I think we're ready to come here and play them on even terms,” midfielder Michael Bradley told reporters, according to ESPN and Soccer By Ives. “The pressure for them, at home, at Azteca, to come out and not only play a good game, but to win, is huge.”

What to watch for as the rivalry is renewed:

Ghosts of Azteca

The U.S. was 0-23-1 on Mexican soil until last August, when U.S. coach Jurgen Klinsmann brought a makeshift team to the Azteca for what appeared to be an ill-advised exhibition and escaped with an historic 1-0 win.

There are plenty of reasons to discount that result—it was a friendly, the stadium wasn’t full, there were loads of big names missing, etc. But in the minds of the U.S., the difference between “never” and “once” could be vast. If it’s been done before, it can be done again.

“We’ll have to walk down that tunnel again and there will be a lot of fear and a lot of anxiety,” goalkeeper Tim Howard said following the win. “But we’ll step out there and feel like we know how to win.”

Among the 11 Americans who started that day, only four are currently in camp—defender Geoff Cameron, midfielders Maurice Edu and Kyle Beckerman and forward Herculez Gomez. U.S. fans will have to hope that the confidence acquired seven months ago somehow translates to the current group.

The odds remain long. Mexico is 68-1-6 all-time in qualifiers at the Azteca, which seats around 104,000 fans and is located in the thin, gritty Mexico City air some 7,200 feet above sea level.

After the U.S. failed to hold a lead and lost, 2-1, in the ’09 qualifier, Landon Donovan said that playing at Azteca “wears you out. It’s just exhausting.” He reportedly had a cup of vomit thrown at him while taking a corner kick. Howard said the ball “moved differently” there.

A good result shouldn’t be expected. But if it somehow happens, it would put the U.S. well on its way to a spot in Brazil.

Tactical questions

Klinsmann got it right in Friday’s win over Costa Rica. There was experience in back and width in midfield—two key elements that helped the U.S. weather the literal storm and move the ball more effectively in several inches of snow than it did in the February loss to Honduras.

“When you look at the guys we had on the field, I think it helped a little bit in terms of the natural flow of the game,” striker Jozy Altidore said “If you want to be successful against these teams, we’ve got to play some quality soccer.”

The manager won’t be able to field the same lineup that took maximum points at Dick’s Sporting Goods Park on Friday thanks to midfielder Jermaine Jones’ ankle injury. But he hinted Monday when speaking to reporters in Mexico City that he’s leaning toward continuity, which is a welcome sign for a team that now has played with 24 different starting lineups in the coach’s 24 games in charge.

That means the same 4-4-2 formation (or 4-2-3-1 if one considers Clint Dempsey a withdrawn playmaker) that proved effective against Costa Rica could be in the cards.

There may be concerns with a lack of speed in central defense, where Omar Gonzalez and Clarence Goodson played on Friday, but Klinsmann has several options there if he chooses to make a change.

The coach could push Cameron back inside and deploy Justin Morrow on the right flank, or he could leave Cameron there and push Maurice Edu back into defense. The Bursaspor player partnered with Cameron during the August triumph. Sporting Kansas City’s Matt Besler is available as well.

DaMarcus Beasley, who played left back against Costa Rica, almost surely will keep his spot following a man-of-the-match performance in his first U.S. start since 2010. His experience in Mexico, where he plays for Puebla FC, will be a bonus on Tuesday.

“He’s a consummate pro,” Santos Laguna’s Gomez said of Beasley. “He’s just going to give 100 (percent) for sure, and more. He’s a good player, and I don’t think there’s anybody on our team that won’t tell you that.”

Edu, Kyle Beckerman and Sacha Kljestan are among Klinsmann’s options to replace Jones. Graham Zusi, a more offensive player, may be removed from the starting 11 as well if Klinsmann decides to approach the game a bit more conservatively. The manager also will have to pay attention to Dempsey’s fitness. The national team’s leading goal scorer went 90 minutes in the snow on Thursday in his first full game for club or country in six weeks.

Changes are a given, but Klinsmann’s desire to maintain some continuity should put the U.S. in decent position.

Tri in trouble?

After failing to score against Jamaica in February’s Hex opener and then blowing a two-goal lead in Honduras last week, some are wondering whether Mexico may have peaked too early.

In addition, coach Jose Manuel de la Torre has a few selection headaches of his own. Olympic hero Oribe Peralta, Gomez’s Santos teammate, is out with a knee injury, and two starting defenders, center back Francisco Rodriguez and left back Jorge Torres Nilo, are suspended for Tuesday’s game. Plugging those holes could lead to some extensive shuffling in midfield.

Regardless, Mexico has enough talent going forward to break open a game. Manchester United’s Javier “Chicharito” Hernandez scored both goals in the 2-2 draw in Honduras and is as difficult to mark as any forward the U.S. has faced. In addition, skillful attackers Andres Guardado and Giovani dos Santos have given the Americans fits in the past.

Bradley said Monday that his team’s confidence and commitment to closing down Mexico’s offensive players will be key to creating the right atmosphere for an upset.

“At a certain point there’s a chance the crowd could turn on them,” he told Soccer by Ives. “We have to understand the situation and know that there will be big pressure on them to come out and play a good game from the start, so we have to know how to deal with that.”